What is Panosteitis?

Panosteitis is an inflammatory condition affecting the long bones (humerus, radius or ulna in the fore legs, and femur or tibia in the hind limbs) of puppies and adolescent dogs which is characterised by lameness (often shifting from leg to leg). Fore-limb lameness is most common. Panosteitis is sometimes simply referred to as “growing pains”. The normal process of bone degeneration and resorption fails to occur; and as a result, there is an excess formation and thickening of bone.

What Causes Panosteitis?

The exact cause of panosteitis remains unknown. It is believed to be multifactorial with genetic links. In nutritional terms, over-feeding and providing a puppy with an unbalanced calcium to phosphorous ratio may be to blame. Stress, metabolic factors and autoimmune components may also be of relevance. Bacterial infection is not thought to be causative since the condition responds poorly to antibiotics, and bacteria have not been isolated when investigative studies have been undertaken. The reason for lameness is the pressure within the bone and / or the stimulation of pain receptors in the periosteum (the soft tissue lining of the bone).

What Dogs are Most at Risk?

• Panosteitis is most common in puppies and adolescent dogs aged from 5-18 months (although the condition can affect a dog at any age)
• Male dogs (although bitches can be affected too)
• Certain breeds including the German Shepherd, Great Dane, Golden Retriever, Labrador Retriever, Rottweiler, Doberman and Basset Hound.
• Puppies who are over-fed or fed an unbalanced diet may be more at risk

Symptoms

Symptoms usually include:-

• An acute onset of unexplained lameness that cannot be attributed to trauma / injury (the humerus is the bone most often affected)
• A shifting pattern of lameness moving from limb to limb
• Lameness that waxes and wanes (i.e. there are periods of deterioration followed by periods of improvement)
• A high temperature
• Lethargy
• Inappetence (with resultant weight loss if long-term)
• Muscle atrophy

Any case of suspected panosteitis warrants veterinary intervention as the sooner the condition is diagnosed, the sooner appropriate treatment can commence. This can help to minimise the risk of weight loss and muscle tone. The condition is painful, so although the condition will eventually correct itself, it is important to ensure that suitable pain relief is given. Also, long-term swelling affecting the growth plates can result in permanent damage.

Diagnosing EPI

Initially your vet will carry out a physical examination; monitoring the dog’s response to pressure applied to the bones. Radiography is carried out to confirm the diagnosis, and the vet will be looking for the characteristic increase in the density of the affected bones (some x-rays do however show no visible abnormalities, particularly if the condition has come on very recently). A blood sample may also be recommended, and your vet will be looking for an increased white cell count. As the problem does spontaneously resolve, it may be felt that diagnostic tests are unnecessary, but it is important to rule out other more serious causes of lameness.

Therapy

Analgesia is necessary as the condition is painful. Anti-inflammatory drugs may be required in moderate to severe cases of lameness, and restricted exercise is essential.

Nutritional Management

Because the panosteitis has not been confirmed as a nutritionally responsive medical condition, there are not any specific dietary recommendations. However, the following may be helpful:-

1. A puppy with panosteitis requires restricted exercise. As he will not be burning so many calories, he may well require a reduction to his food allowance whilst he is resting and recuperating. It is essential to keep him at a healthy weight to avoid extra pressure on his limbs.
2. Ensure that your chosen diet is balanced and contains all of the nutrients your puppy needs at the correct level; don’t add extra vitamins or minerals unless your vet has specifically recommended this. The diet should not be overly high in fat (or calories), and formulated to promote slow and steady growth.
3. Some neutraceutical supplements may be of benefit. Do discuss their use with your vet beforehand. These may include:-

Glucosamine - Glucosamine provides the building blocks to synthesise new joint cartilage. Although panosteitis is a condition of the long bones, additional joint protection could be beneficial.

Chondroitin - Chondroitin blocks destructive enzymes that break down cartilage in the joint. There is always a low level of these destructive enzymes in the joint, but when injury or abnormal wear occurs the enzymes multiply. As per glucosamine, although panosteitis affects the long bones, the joints may benefit from extra support.

MSM – Methyl-sulphonyl-methane is an organic form of sulphur which help relieve pain and inflammation. (It should not however be used as a substitute for conventional analgesic drugs).

Essential fatty acids –The Omega-3 fatty acids DHA and EPA have anti-inflammatory properties, whilst the Omega-6 fatty acids have lubricant properties. A good quality fish oil supplement is a good way to boost these beneficial fats.

Antioxidant plant extracts –Many commercial pet foods include ingredients such as yucca or cranberry which are a good source of antioxidants which protect the body from free radical damage. The body releases more free radicals when it is under stress from illness.